OCCURRENCE OF THE POTENTIALLY TOXIC DINOFLAGELLATE Ostreopsis ovata ALONG THE APULIAN COASTAL AREAS (SOUTHERN ITALY) AND RELATIONSHIP WITH ANTHROPOGENIC POLLUTION

The monitoring of the epi-benthic dinoflagellate Ostreopsis ovata was carried out during the summer seasons of 2007 and 2008 all along the marine coastal areas of the Puglia region (Southern Italy, Central Mediterranean). Eighteen monitoring sites were investigated in both years from June to September at 15 day-time intervals, collecting water samples in order to measure both the Ostreopsis ovata density and microbiological parameters (Fecal Coliforms and Streptococci). The microbiological parameters were measured as indirect indicators of pollution from anthropogenic sources. Ostreopsis ovata highest density values were estimated for both years in the monitoring sites located northbound from the town of Bari, on the southern Adriatic coast. Results from microbiological analysis showed a similar distribution pattern. The relationship between O. ovata abundance and microbiological pollution was investigated by using synthetic indices (Ostreopsis-Score and Bacteriological Quality Index respectively) and the correspondence between the dinoflagellate blooms and human-induced pollution pressures on these marine coastal areas was highlighted.